Mixer-grinder,especially for foundry sands



States Patent ()7 3,454,232 MIXER-GRINDER, ESPECIALLY FOR FOUNDRY SANDS Robert A. M. Ronceray, 122 Ave. des Champs Elysees, Paris, France; Lena Sarah Yeomans, Andree Jacqueline Laure Ronceray, Francoise Monique Mary Ronceray, and Pierre Robert Ronceray, heirs of said Robert A. M. Ronceray, deceased Filed May 8, 1964, Ser. No. 365,993 Claims priority, appligaaio: France, May 10, 1963,

25 Int. Cl. B02c 7/16, 19/00, 17/16 US. Cl. 241-110 Claim The present invention has for its object, by way of providing a novel industrial product, an apparatus which carries out the mixing and grinding of granular products, especially although not exclusively products such as foundry sands; this apparatus will be designated hereinafter as a mixer-grinder.

The primary object of the invention is to provide a mixer-grinder which permits the possibility of obtaining a final product which has been subjected to a powerful stirring action and which is both homogeneous and well aerated.

Another object of the invention is to provide a mixergrinder having a base which provides perfect clearance for the purpose of facilitating discharge, in particular the mechanical removal of products which have been processed.

A further object of the invention is to provide a mixergrinder in which the working members thereof are readily accessible and are subject to minimum wear.

In order to achieve the different objects outlined above as well as other objects which will become apparent from the remaining description which now follows, a mixergrinder in accordance with the invention consists mainly of a stationary tank, a driving unit comprising a motor properly located outside said tank and a reduction-gear unit which is placed within said tank, and an arm or crosshead which is keyed on the output shaft of the reduction-gear unit and which is adapted to support all the moving working-members.

The moving working-members mainly consist of mullers and scarifying discs which are intended to effect the mixing and grinding of the product and at least one scraper which is intended to facilitate the discharge of the product which as been processed.

According to an advantageous form of embodiment of the invention, both the mullers and the scraper are mounted on the arm in such a manner as to be capable of moving towards or away from the base of the tank; the movements of these two components are preferably coordinated in such manner as to ensure that, when the mullers are in the working position, the scraper is lifted into the inoperative position and conversely.

Further characteristic features and advantages of the invention will be brought out by the description which follows below, reference being made to the accompanying drawings which are given by way of example without any implied limitation, and in which:

FIG. 1 is a sectional view of a machine in accordance with the invention, substantially as viewed from the cutting line I-I in FIG. 2;

FIG. 2 is a cross-section taken along the line II-II of FIG. 1;

FIG. 3 is a cross-section taken along the line IIIIII of FIG. 1.

In the mode of execution which is illustrated in the is mounted at a certain distance above the ground and drawings, the mixer-grinder comprises a tank 1 which carried by stringers 4 on standards such as the standards 3,454,232 Patented July 8, 1969 2, 3. This arrangement serves to maintain the base 5 of said tank at a suflicien-t distance above the ground to permit the ready removal of the processed product, if necessary by mechanical means.

There is mounted in the interior of said stationary tank a reduction-gear unit 6, the input shaft of which projects at 7 at the bottom portion of the tank and is driven in rotation by means of a pulley 8 which is coupled with the pulley 9 of a motor 10 by means of a driving-belt 11. The said motor is mounted substantially at the same height as the tank in such manner as to leave a clearance beneath the base of the machine. There is mounted on the output shaft of the aforesaid reduction-gear unit an arm or crosshead 12 which is therefore driven in rotation and which carries all the working members of the machine. These members mainly consist of scarifying discs 13, 14, 15, 1-6, which are in this case mounted in pairs on shafts 17, 18 through the intermediary of vertical rods 19, 20, 21 and 22 thereby permitting the possibility, as is more clearly shown in FIG. 1, of adjusting the angle which is made by the plane of each disc with a vertical radial plane of the tank in such manner that, when the moving system is in motion, the series of discs produces action on the entire mass of granular product to be processed with a view to dividing the product as well as effecting the displacement and mixing thereof.

The mullers 23 and 24 are placed in diametrically opposite relation and are rotatably mounted on shafts 25, 26 carried by crank arms 27, 28 which are pivotally mounted on the arm 12 by shafts 29 and 30. As illustrated in FIGURE 1, the shafts 29 and 30 extend through the crosshead 12 with the crank arms 27 and 28 being connected to one end of the shafts 29 and 30, respectively, the other ends, of the shafts 29 and 30 being connected to the levers 31 and 32, respectively. The crank arm 27, shaft 29 and lever 31 function as one bell-crank, while the crank arm 28, shaft 30 and lever 32 function as another .bell-crank, A jack or fluid pressure actuated cylinder 33, which is supplied with compressed air through a rotary seal 34, is mounted between the oppositely facing free upper ends of said levers 31 and 32.

As illustrated in FIGURE 2, the cylinder 33 is provided with a piston rod 43 the end of which is pivotally connected to the lever 31 by means of the pivot pin 44. The other end of the cylinder 33 is provided with flanges 45 pivotally connected to the upper end of the lever 32 by means of a pivot pin 46. Thus, the levers 31 and 32 support the cylinder 33 relative to the tank whereby both the cylinder housing and the piston rod can move relative to each other and to the surrounding tank 1. Thus, energization of the cylinder 33 by means of compressed air will cause the cylinder and the piston rod thereof to move from their solid line position indicated in FIGURE 2 to their dotted line position. The resulting pivotable movement of the levers 31 and 32 causes a corresponding pivotable movement of the arms 27 and 28 whereby the mullers 23 and 24 are raised into their elevated positions indicated in dotted lines in FIGURE 3.

As illustrated in FIGURE 3, the rotary seal 34 for supplying pressurized fluid to the cylinder includes a lower portion 50 fixedly secured by the upright member 51 to the crosshead 12 for rotation therewith. The seal 34 has an upper portion 52 which is connected to a sta tionary arch 53 secured to the tank 1 for maintaining the seal in the desired position. Pressurized fluid is then supplied through the rotary seal 34 to the cylinder 33 by conventional conduit means, not shown.

Finally, the mixer-grinder comprises a scraper 35 mounted at the end of an arm 36 which is secured to the sleeve 37 pivotally mounted on the shaft 17. The arm 36 has a rod 48 near the sleeve 37 which is connected by means, such as a chain 49, to a pin 47 mounted on the lever 31. Thus, when the mullers are in their lowered positions adjacent the bottom of the tank, the scraper will be held in its upper, solid line position of FIGURE 3 by said chain 49. When the mullers are moved into their upper positions, as indicated by dotted lines in FIGURE 3, the scraper will drop into its lowered position adjacent the base of the tank, also indicated by dotted lines in FIGURE 3, under the force of gravity. A stud 38 is provided on that end of the arm 36 which is opposite to the scraper 35 proper.

In the position which is shown in the drawings that is to say in the retracted position of the jack 33, the mullers are in their lowered positions and produce action on the granular material which is contained in the tank so as to crush said material and break up the lumps. The pressure with which the mullers 23, 24 are applied against the granular material can be adjusted by regulating the pressure of compressed air which is admitted into 'the air cylinder 33.

In the reverse position of the cylinder 33, the mullers are lifted and, on the other hand, the scrapper is lowered as shown in dotted lines in FIG. 3. At this moment, action can be produced simultaneously on the jacks 39, 40 so as to operate respectively the gates 41, 42 which, in the working position, close the corresponding openings formed in the base of the tank. The said gates are then brought into the position which is shown in dotted lines in FIG. 3, thereby permitting the contents of the tank to be removed rapidly at the end of the work cycle by means of'the scraper 35.

As will readily be understood, the modes of execution combination a stationary tank, a driving unit consisting of a motor located outside the tank and of a reductiongear unit placed Within said tank, a crosshead keyed on the output shaft of said reduction-gear unit, two mullers and one scraper which are pivotally mounted on said crosshead and an articulated coupling between said mullers and said scraper and so designed that, when the mullers are in the bottom position in the vicinity of the base of the tank, the scraper is accordingly located at a distance from said base and conversely.

References Cited UNITED STATES PATENTS 1,857,337 5/1932 Simpson 241-128 2,103,895 12/1937 Christensen 241128 2,610,802 9/1952 McIlvaine 241128 2,630,975 3/1953 Horth 241132 2,998,935 9/1961 Pellizzetti 241133 X ROBERT C. RIORDON, Primary Examiner.

D. G. KELLEY, Assistant Examiner.

US. Cl. X.R. 

1. MIXER-GRINDER OF THE TYPE SPECIFIED, COMPRISING IN COMBINATION A STATIONARY TANK, A DRIVING UNIT CONSISTING OF A MOTOR LOCATED OUTSIDE THE TANK AND OF A REDUCTIONGEAR UNIT PLACED WITHIN SAID TANK, A CROSSHEAD KEYED ON THE OUTPUT SHAFT OF SAID REDUCTION-GEAR UNIT, TWO MULLERS AND ONE SCRAPER WHICH ARE PIVOTALLY MOUNTED ON SAID CROSSHEAD AND AN ARTICULATED COUPLING BETWEEN SAID MULLERS AND SAID SCRAPER AND SO DESIGNED THAT, WHEN THE MULLERS ARE IN THE BOTTOM POSITION IN THE VICINITY OF THE BASE OF THE TANK, THE SCRAPER IS ACCORDINGLY LOCATED AT A DISTANCE FROM SAID BASE AND CONVERSELY. 